Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire n...Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire networks(NWs) with rich interfaces and defects supported on carbon(RuO_(2)-PdO NWs/C) for alkaline hydrogen oxidation reaction(HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time.As expected,the RuO_(2)-PdO NWs/C(72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density(jo,m) of 1061 A gRuPd-1,which is 3.1 times of commercial Pt/C and better than most of the reported nonPt noble metal HOR electrocatalysts.Even at the high potential(~0.5 V vs.RHE) or the presence of CO(5 vol%),the RuO_(2)-PdO NWs/C still effectively catalyzes the alkaline HOR.Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO_(2) and PdO act as the active sites.The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had,also strengthen the adsorption of OHad,and accelerate the alkaline HOR process.Moreover,OHadon RuO_(2) can spillover to the interfaces,keeping the RuO_(2)-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning.展开更多
The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR ...The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR kinetics in alkaline is two to three orders of magnitude slower than that in acid.More critically,fundamental understanding of the sluggish kinetics derived from the p H effect is still debatable.In this review,the recent development of understanding HOR mechanism and rational design of advanced HOR electrocatalysts are summarized.First,recent advances in the theories focusing on fundamental understandings of HOR under alkaline electrolyte are comprehensively discussed.Then,from the aspect of intermediates binding energy,optimizing hydrogen binding energy(HBE)and increasing hydroxyl binding energy(OHBE),the strategies for designing efficient alkaline HOR catalysts are summarized.At last,perspectives for the future research on alkaline HOR are pointed out.展开更多
This work demonstrates the outstanding performance of alloyed Au1 Pt1 nanoparticles on hydrogen oxidation reaction(HOR)in alkaline solution.Due to the weakened hydrogen binding energy caused by uniform incorporation o...This work demonstrates the outstanding performance of alloyed Au1 Pt1 nanoparticles on hydrogen oxidation reaction(HOR)in alkaline solution.Due to the weakened hydrogen binding energy caused by uniform incorporation of Au,the alloyed Au1Pt1/C nanoparticles exhibit superior HOR activity than commercial PtRu/C.On the contrary,the catalytic performance of the phase-segregated Au2Pt1/C and Au1Pt1/C bimetallic nanoparticles in HOR is significantly worse.Moreover,Au1Pt1/C shows a remarkable durability with activity dropping only 4% after 3000 CV cycles,while performance attenuation of commercial PtRu/C is high up to 15% under the same condition.Our results indicate that the alloyed Au1Pt1/C is a promising candidate to substitute commercial PtRu/C for hydrogen oxidation reaction in alkaline electrolyte.展开更多
To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely important.Hydrogen fuel cells are an important system for converti...To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely important.Hydrogen fuel cells are an important system for converting hydrogen energy into electrical energy.However,the slow hydrogen oxidation reaction(HOR)kinetics under alkaline conditions has limited its development.Therefore,elucidating the catalytic mechanism of HOR in acidic and alkaline media is of great significance for the construction of highly active and stable catalysts.In terms of practicality,Pt is still the primary choice for commercialization of fuel cells.On the above basis,we first introduced the hydrogen binding energy theory and bifunctional theory used to describe the HOR activity,as well as the pH dependence.After that,the rational design strategies of Pt-based HOR catalysts were systematically classified and summarized from the perspective of activity descriptors.In addition,we further emphasized the importance of theoretical simulations and in situ characterization in revealing the HOR mechanism,which is crucial for the rational design of catalysts.Moreover,the practical application of Pt-based HOR catalysts in fuel cells was also presented.In closing,the current challenges and future development directions of HOR catalysts were discussed.This review will provide a deep understanding for exploring the mechanism of highly efficient HOR catalysts and the development of fuel cells.展开更多
Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocataly...Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocatalysts have been widely investigated toward hydrogen oxidation reaction(HOR)under alkaline electrolytes,these studies are mostly limited to conventional hexagonal-close-packed(hcp)phase,mainly arising from the lack of sufficient synthesis strategies.In this study,we report the precise synthesis of metastable binary RuW alloy with face-centered-cubic(fcc)phase.We find that the introduction of W can serve as fcc phase seeds and reduce the formation energy of metastable fcc-RuW alloy.Impressively,fcc-RuW exhibits remarkable alkaline HOR performance and stability with the activity of 0.67 mA cm_(Ru)^(-2)which is almost five and three times higher than that of hcp-Ru and commercial Pt/C,respectively,which is attributed to the optimized binding strength of adsorbed hydroxide intermediate derived from tailored electronic structure through W doping and phase engineering.Moreover,this strategy can also be applied to synthesize other metastable fcc-RuCr and fcc-RuMo alloys with enhanced HOR performances.展开更多
The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to ...The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to modulate its catalytic HOR performance,but at the cost of mass activity due to the coverage of modifiers on Pt surface.Herein,we constructed dual junctions'Pt/nitrogen-doped carbon(Pt/NC)andδ-MoC/NC to modify electronic structure of Pt via interfacial electron transfer to acquire Pt-MoC@NC catalyst with electron-deficient Pt nanoparticles,simultaneously endowing it with high mass activity and durability of alkaline HOR.Moreover,the unique structure of Pt-MoC@NC endows Pt with a high COtolerance at 1,000 ppm CO/H_(2),a quality that commercial Pt-C catalyst lacks.The theoretical calculations not only confirm the diffusion of electrons from Pt/NC to Mo C/NC could occur,but also demonstrate the negative shift of Pt d-band center for the optimized binding energies of*H,*OH and CO.展开更多
The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic...The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.展开更多
As a carbon-free energy carrier,hydrogen has become the pivot for future clean energy,while efficient hydrogen production and combustion still require precious metal-based catalysts.Single-atom catalysts(SACs)with hig...As a carbon-free energy carrier,hydrogen has become the pivot for future clean energy,while efficient hydrogen production and combustion still require precious metal-based catalysts.Single-atom catalysts(SACs)with high atomic utilization open up a desirable perspective for the scale applications of precious metals,but the general and facile preparation of various precious metal-based SACs remains challenging.Herein,a general movable printing method has been developed to synthesize various precious metal-based SACs,such as Pd,Pt,Rh,Ir,and Ru,and the features of highly dispersed single atoms with nitrogen coordination have been identified by comprehensive characterizations.More importantly,the synthesized Pt-and Ru-based SACs exhibit much higher activities than their corresponding nanoparticle counterparts for hydrogen oxidation reaction and hydrogen evolution reaction(HER).In addition,the Pd-based SAC delivers an excellent activity for photocatalytic hydrogen evolution.Especially for the superior mass activity of Ru-based SACs toward HER,density functional theory calculations confirmed that the adsorption of the hydrogen atom has a significant effect on the spin state and electronic structure of the catalysts.展开更多
Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte ...Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte fuel cells(APEFCs).Herein,we report the synthesis of amorphous RuCr nanosheets with different molar ratios and their HOR performances under alkaline media.We find a volcano correlation between the Cr content in RuCr nanosheets and their alkaline HOR performance.Experimental results and density functional theory(DFT)calculation reveals that the optimized Cr content in RuCr nanosheets could lead to the optimum hydroxide binding energy(OHBE),contributes to their remarkable alkaline HOR performance with mass activity of 568.1 A·gPGM^(–1) at 50 mV,13-fold higher than that of Ru catalyst.When RuCr nanosheet is further used as the anodic electrocatalyst,a peak power density of 1.04 W·cm^(–2 )can be achieved in an APEFC.展开更多
The regulation of interface electron-transfer and catalytic kinetics is very important to design the efficient electrocatalyst for alkaline hydrogen oxidation reaction(HOR).Here,we show the Pt-Ni alloy nanoparticles(P...The regulation of interface electron-transfer and catalytic kinetics is very important to design the efficient electrocatalyst for alkaline hydrogen oxidation reaction(HOR).Here,we show the Pt-Ni alloy nanoparticles(PtNi_(2))have an enhanced HOR activity compared with single component Pt catalyst.While,the interface electron-transfer kinetics of PtNi_(2)catalyst exhibits a very wide electron-transfer speed distribution.When combined with carbon dots(CDs),the interface charge transfer of PtNi_(2)-CDs composite is optimized,and then the PtNi_(2)-5 mg CDs exhibits about 2.67 times and 4.04 times higher mass and specific activity in 0.1 M KOH than that of 20%commercial Pt/C.In this system,CDs also contribute to trapping H^(+)and H_(2)O generated during HOR,tuning hydrogen binding energy(HBE),and regulating interface electron transfer.This work provides a deep understanding of the interface catalytic kinetics of Pt-based alloys towards highly efficient HOR catalysts design.展开更多
The hydrogen evolution reaction(HER)is the cathodic process of water splitting,and its reverse,the hydrogen oxidation reaction(HOR),is the anodic process of an H-Ofuel cell;both play important roles in the development...The hydrogen evolution reaction(HER)is the cathodic process of water splitting,and its reverse,the hydrogen oxidation reaction(HOR),is the anodic process of an H-Ofuel cell;both play important roles in the development of hydrogen energy.The rational design and scalable fabrication of low-cost and efficient bifunctional catalysts for the HER/HOR are highly desirable.Herein,ultrasmall Mo-Ru nanoalloy(Mo_(0.5)Ru_(3)and Mo_(0.5)Ru_(3))particles uniformly distributed on mesoporous carbon(MPC)were successfully synthesized by a simple method that is easy to scale up for mass production.After the incorporation of Mo atoms,the as-prepared Mo_(0.5)Ru_(3)and Mo_(0.5)Ru_(3)nanoalloys maintain a hexagonal-close-packed crystal structure.In acidic media,Mo_(0.5)Ru_(3)exhibits excellent Pt-like HER and HOR activity,as well as good stability.Density functional theory(DFT)calculations reveal that the H adsorption free energy(ΔG)on the Mo_(0.5)Ru_(3)(001)surface(-0.09 eV)is much closer to zero than that of metallic Ru(-0.22 eV),which contributes to the enhanced catalytic activity.In alkaline media,Mo_(0.5)Ru_(3)also presents outstanding HER and HOR activity,even significantly outperforming Pt/C.The DFT results confirm that optimal binding energies with H*and OH*intermediate species,and low energy barriers in the water dissociation and formation steps,efficiently accelerate the alkaline HER/HOR kinetics of Mo_(0.5)Ru_(3).This study provides a new avenue for the scalable fabrication of high-efficiency bifunctional electrocatalysts for the HER and HOR in both acidic and alkaline media.展开更多
Precisely controlling the crystalline phase structure and exposed facets at the atomic level opens up a new avenue for efficient catalyst design.Along this line,we report an unconventional face-centered cubic(fcc)Ru w...Precisely controlling the crystalline phase structure and exposed facets at the atomic level opens up a new avenue for efficient catalyst design.Along this line,we report an unconventional face-centered cubic(fcc)Ru with twinned structure and stacking-fault defects as a competent electrocatalyst towards alkaline hydrogen oxidation reaction(HOR),which is now a major obstacle for the commercialization of anion exchange membrane fuel cells(AEMFC).With conventional hexagonal close packing(hcp)Ru as the counterpart,a novel scope from the phase-engineering is introduced to identify the activity origin and provide fundamental understanding of the sluggish HOR kinetics in alkaline medium.Systematic electrochemical analysis assisted by deconvoluting the hydrogen(H)desorption peaks indicates the superior performance of fcc Ru origins from the structure defects and higher proportion of the most active sites.DFT calculations,together with CO-stripping voltammograns further corroborate the stronger hydroxyl species(OH^(*))affinity lead to the higher activity on these sites.Meanwhile,it also demonstrates the H^(*)adsorption/desorption on polycrystalline Ru among the conventional"hydrogen region"is accompanied by the surface bound OH^(*)in alkaline medium,which is of great significance for subsequent alkaline HOR exploration and catalyst design.展开更多
In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBC...In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBCs).For this purpose,polyethyleneimine(PEI) was added onto the reduced graphene oxide and CoPc composite(RGO/CoPc) to create abundant NH2 axial ligand groups,for anchoring the Co core within the CoPc.Owing to the PEI addition,the onset potential of the hydrogen peroxide oxidation reaction was shifted by 0.13 V in the negative direction(0.02 V) and the current density was improved by 1.92 times(1.297 mA cm^(-2)),compared to those for RGO/CoPc(0.15 V and 0.676 mA cm^(-2),respectively),due to the formation of donor-acceptor dyads and the prevention of CoPc from leaching out.The biocatalyst using glucose oxidase(GOx)([RGO/CoPc]/PEI/GOx) showed a better onset potential and catalytic activity(0.15 V and 318.7 μA cm^(-2)) than comparable structures,as well as significantly improved operational durability and long-term stability.This is also attributed to PEI,which created a favorable microenvironment for the enzyme.The maximum power densities(MPDs) and open-circuit voltages(OCVs) obtained for HPFCs and EBCs using the suggested catalyst were 105.2±1.3 μW cm^(-2)(0.317±0.003 V) and 25.4±0.9 μW cm^(-2)(0.283±0.007 V),respectively.This shows that the amine axial ligand effectively improves the performance of the actual driving HPFCs and EBCs.展开更多
Controlling the particle size of catalyst to understand the active sites is the key to design efficient electrocatalysts toward hydrogen electrode reactions including hydrogen oxidation and evolution(HOR/HER).Herein, ...Controlling the particle size of catalyst to understand the active sites is the key to design efficient electrocatalysts toward hydrogen electrode reactions including hydrogen oxidation and evolution(HOR/HER).Herein, the hydrogen and hydroxyl adsorption on Ru/C could be effectively tuned for HOR/HER by simple controlling the particle sizes. It is found that the metallic Ru(Ru0) is the active site for HOR/HER, while oxidized Ru(Rux+) will hinder the adsorption and desorption of hydrogen on the catalyst. For the HOR,catalyst with small particles is more efficient, due to it is a three-phase interface reaction of gas on the surface of the catalyst. For the HER, the metallic state of Ru is crucial. The deconvolution of hydrogen peaks indicates that the catalytic sites with low hydrogen binding energy(HBE) shoulder the majority of the HOR activity. CO stripping curve further demonstrates that the stronger hydroxyl species(OHad)affinity is beneficial to promote the HOR performance. The results indicate that the design of efficient HOR/HER catalyst should focus on the balance between particle size and metallic states.展开更多
Recent advancement of proton exchange membrane fuel cells has led to commercial sales of fuel-cell cars but market barrier exists because this technology heavily relies on platinum catalyst.Given the permission of ado...Recent advancement of proton exchange membrane fuel cells has led to commercial sales of fuel-cell cars but market barrier exists because this technology heavily relies on platinum catalyst.Given the permission of adopting platinum-group-metal-free catalysts,anion-exchange membrane fuel cell has received notable attention.However,the sluggish kinetics of anodic hydrogen oxidation reaction(HOR)largely limit the cell efficiency.Although many high-performance HOR catalysts have been reported,there are analytical uncertainties in the literature concerning the assessment of the catalyst activity.Here we determine the origin of false HOR currents in the recorded polarization curves and propose a rigorous approach to eliminate them.We unveil experimentally the uncertainties of obtaining exchange current densities(j0)using Tafel plot from Bulter–Volmer equation and recommend employing the micro-polarization region method.For bulky catalysts that cannot establish a well-defined diffusion layer,we suggest applying external stirring bar to offer certain level of enforced convection and using j0 to compare the activity.展开更多
Modulating Pt surfaces through the introduction of lattice distortion emerges as immensely effective strategy that enhances the kinetics of alkaline hydrogen evolution and oxidation processes.In this study,we fabricat...Modulating Pt surfaces through the introduction of lattice distortion emerges as immensely effective strategy that enhances the kinetics of alkaline hydrogen evolution and oxidation processes.In this study,we fabricated lattice-distorted Pt wrinkled nanoparticles(LD-Pt WNPs)for efficient hydrogen electrocatalysis.The LD-Pt WNPs not only outperform the Pt/C benchmark in hydrogen oxidation reaction,achieving an excellent mass-specific current of 968.5 mA·mg_(Pt)^(-1)(9 times that of Pt/C),but also demonstrate outstanding hydrogen evolution reaction activity with a small overpotential of 58.0 mV.Comprehensive experiments and density functional theory calculations reveal that lattice defects introduce an abundance of unsaturated coordination atoms while modifying the d-band center of Pt.This dual effect optimizes the binding strength of crucial H and OH intermediates,leading to a significant reduction in the energy barrier of the reaction bottleneck,commonly known as the Volmer step.This work unveils a fresh viewpoint on projecting and developing high efficiency electrocatalysts through defect engineering.展开更多
Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER)is of considerable importance for the industrial production of gr...Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER)is of considerable importance for the industrial production of green and sustainable energy.Here,an ultrathin Ir-Sb nanowires(Ir-Sb NWs)protected by antimony oxides(SbO_(x))was synthesized as an efficient bifunctional catalyst for both HOR and HER under alkaline media.Except from the much higher mass activities of Ir-Sb nanowires than those of Ir nanowires(Ir NWs)and commercial Pt/C,the SbO_(x) protective layer also contributes to the maintenance of morphology and anti-CO poisoning ability,leading to the long-term cycling performance in the presence of CO.Specifically,the Ir-Sb NW/SbO_(x) exhibits the highest catalytic activities,which are about 3.5 and 4.8 times to those of Ir NW/C and commercial Pt/C toward HOR,respectively.This work provides that the ultrathin morphology and H_(2)O-occupied Sb sites can exert the intrinsic high activity of Ir and effectively optimize the absorption of OH*both in alkaline HER/HOR electrolysis.展开更多
Efficient,robust and cost-effective electrocatalysts that catalyze hydrogen evolution/oxidation reaction(HER/HOR)in alkaline media are highly demanded.Recently,single-atom catalysts(SACs)have emerged as new promising ...Efficient,robust and cost-effective electrocatalysts that catalyze hydrogen evolution/oxidation reaction(HER/HOR)in alkaline media are highly demanded.Recently,single-atom catalysts(SACs)have emerged as new promising candidates;however,the rational design of supports and the optimization of coordination environment between supports and metal atoms are challenging.In this work,we successfully fabricate atomically dispersed ruthenium(Ru)species,which are strongly coordinated by N and S dual heteroatoms on holey graphene(RuSA/NSG),as an excellent bifunctional catalyst for HER/HOR.In alkaline media,the developed catalyst exhibits high catalytic performance with a low overpotential of 57.3 mV to drive a current density of 10 mA cm^(-1) for HER,and its mass activity is about 5.8 times higher than that of commercial Pt/C and Ru/C catalysts at an overpotential of 100 mV.Similarly,considerable HOR performance of Ru SA/NSG is verified to be superior to Pt/C and Ru/C.Furthermore,X-ray-based spectroscopy measurements and density-functional theory calculations have confirmed that,compared with Ru–N_(4),the tailored Ru–N_(4)–S_(2) with nearby S dopants can act as more active centers to greatly accelerate the sluggish HER/HOR kinetics in alkaline media.The present work provides a new atomic-level engineering strategy to modulate catalytic activities of SACs via the coordination design using dual heteroatoms on the carbon support.展开更多
Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction(HOR),yet its specific role is largely undecoded.Here,ultrathin Pt nanowires(NWs)ar...Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction(HOR),yet its specific role is largely undecoded.Here,ultrathin Pt nanowires(NWs)are selected as models for revealing the significance of Ni modification on HOR by precisely positioning Ni on distinct positions of Pt NWs.Ni solely influences the electronic properties of Pt and thus weakens*H adsorption when it is located in the core of PtNi alloyed NWs,leading to a moderate improvement of alkaline HOR activity.When Ni is distributed in both core and surface of PtNi alloyed NWs,Ni strongly weakens*H adsorption but strengthens*OH adsorption.On the other hand,the electronic properties of Pt are hardly influenced when Ni is deposited on the surface of Pt NWs,on which the strong*H and*OH adsorptions lead to the improved HOR activity.This work reveals the significance of Ni modification on HOR,but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond.展开更多
Exploring highly efficient electrocatalysts and understanding the reaction mechanisms for hydrogen electrocatalysis,including hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) in alkaline media a...Exploring highly efficient electrocatalysts and understanding the reaction mechanisms for hydrogen electrocatalysis,including hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) in alkaline media are conducive to the conversion of hydrogen energy.Herein,we reported a new strategy to boost the HER/HOR performances of ruthenium (Ru) nanoparticles through nitrogen (N) modification.The obtained N-Ru/C exhibit remarkable catalytic performance,with normalized HOR exchange current density and mass activity of 0.56 m A/cm^(2)and 0.54 m A/μg,respectively,about 4 and 4.5 times higher than those of Ru/C,and even twofold enhancement compared to commercial Pt/C.Moreover,at the overpotential of 50 m V,the normalized HER current density of N-Ru/C is 5.5 times higher than that of Ru/C.Experimental and density functional theory (DFT) results verify the electronic regulation of Ru after N incorporation,resulting in the optimized hydrogen adsorption Gibbs free energy (ΔG_(H*)) and hence enhancing the HOR/HER performance.展开更多
基金supported by the National Natural Science Foundation of China (22262018)Young Science and Technology Fund in Gansu Province of China (21JR7RA252)+2 种基金Natural Research Fund of Gansu Province (20JR5RA441)Lanzhou Open Competition Mechanism,Merit Based Admission Project Major Fund (2021-JB-6)National Engineering&Fund for National Nickel and Cobalt Advanced Materials Engineering Research Center(GCZX2021JSKF001)。
文摘Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire networks(NWs) with rich interfaces and defects supported on carbon(RuO_(2)-PdO NWs/C) for alkaline hydrogen oxidation reaction(HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time.As expected,the RuO_(2)-PdO NWs/C(72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density(jo,m) of 1061 A gRuPd-1,which is 3.1 times of commercial Pt/C and better than most of the reported nonPt noble metal HOR electrocatalysts.Even at the high potential(~0.5 V vs.RHE) or the presence of CO(5 vol%),the RuO_(2)-PdO NWs/C still effectively catalyzes the alkaline HOR.Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO_(2) and PdO act as the active sites.The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had,also strengthen the adsorption of OHad,and accelerate the alkaline HOR process.Moreover,OHadon RuO_(2) can spillover to the interfaces,keeping the RuO_(2)-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning.
基金financially supported by the National Key Research and Development program of China(2018YFB1502302)the National Natural Science Foundation of China(21972107)+1 种基金the Natural Science Foundation of Hubei Province(2020CFA095)the Natural Science Foundation of Jiangsu Province(BK20191186)。
文摘The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR kinetics in alkaline is two to three orders of magnitude slower than that in acid.More critically,fundamental understanding of the sluggish kinetics derived from the p H effect is still debatable.In this review,the recent development of understanding HOR mechanism and rational design of advanced HOR electrocatalysts are summarized.First,recent advances in the theories focusing on fundamental understandings of HOR under alkaline electrolyte are comprehensively discussed.Then,from the aspect of intermediates binding energy,optimizing hydrogen binding energy(HBE)and increasing hydroxyl binding energy(OHBE),the strategies for designing efficient alkaline HOR catalysts are summarized.At last,perspectives for the future research on alkaline HOR are pointed out.
基金financially supported by the National Natural Science Foundation of China (Grants no. 21376283, 21436003 and 21576032)
文摘This work demonstrates the outstanding performance of alloyed Au1 Pt1 nanoparticles on hydrogen oxidation reaction(HOR)in alkaline solution.Due to the weakened hydrogen binding energy caused by uniform incorporation of Au,the alloyed Au1Pt1/C nanoparticles exhibit superior HOR activity than commercial PtRu/C.On the contrary,the catalytic performance of the phase-segregated Au2Pt1/C and Au1Pt1/C bimetallic nanoparticles in HOR is significantly worse.Moreover,Au1Pt1/C shows a remarkable durability with activity dropping only 4% after 3000 CV cycles,while performance attenuation of commercial PtRu/C is high up to 15% under the same condition.Our results indicate that the alloyed Au1Pt1/C is a promising candidate to substitute commercial PtRu/C for hydrogen oxidation reaction in alkaline electrolyte.
基金support of this research by the National Natural Science Foundation of China(Nos.22179034 and 22279030)the Natural Science Foundation of Heilongjiang Province(No.ZD2023B002).
文摘To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely important.Hydrogen fuel cells are an important system for converting hydrogen energy into electrical energy.However,the slow hydrogen oxidation reaction(HOR)kinetics under alkaline conditions has limited its development.Therefore,elucidating the catalytic mechanism of HOR in acidic and alkaline media is of great significance for the construction of highly active and stable catalysts.In terms of practicality,Pt is still the primary choice for commercialization of fuel cells.On the above basis,we first introduced the hydrogen binding energy theory and bifunctional theory used to describe the HOR activity,as well as the pH dependence.After that,the rational design strategies of Pt-based HOR catalysts were systematically classified and summarized from the perspective of activity descriptors.In addition,we further emphasized the importance of theoretical simulations and in situ characterization in revealing the HOR mechanism,which is crucial for the rational design of catalysts.Moreover,the practical application of Pt-based HOR catalysts in fuel cells was also presented.In closing,the current challenges and future development directions of HOR catalysts were discussed.This review will provide a deep understanding for exploring the mechanism of highly efficient HOR catalysts and the development of fuel cells.
基金the support from the National Natural Science Foundation of China(22272121,21972107)the National Key Research and Development program of China(2021YFB4001200)。
文摘Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocatalysts have been widely investigated toward hydrogen oxidation reaction(HOR)under alkaline electrolytes,these studies are mostly limited to conventional hexagonal-close-packed(hcp)phase,mainly arising from the lack of sufficient synthesis strategies.In this study,we report the precise synthesis of metastable binary RuW alloy with face-centered-cubic(fcc)phase.We find that the introduction of W can serve as fcc phase seeds and reduce the formation energy of metastable fcc-RuW alloy.Impressively,fcc-RuW exhibits remarkable alkaline HOR performance and stability with the activity of 0.67 mA cm_(Ru)^(-2)which is almost five and three times higher than that of hcp-Ru and commercial Pt/C,respectively,which is attributed to the optimized binding strength of adsorbed hydroxide intermediate derived from tailored electronic structure through W doping and phase engineering.Moreover,this strategy can also be applied to synthesize other metastable fcc-RuCr and fcc-RuMo alloys with enhanced HOR performances.
基金supported by the National Natural Science Foundation of China (Grant Nos.52072272,52171145 and 22109120)the Zhejiang Provincial Natural Science Foundation of China (LQ21B030002)+1 种基金the Zhejiang Provincial Special Support Program for High-level Talents (2019R52042)the Key programs for Science and Technology Innovation of Wenzhou (ZG2022037)。
文摘The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to modulate its catalytic HOR performance,but at the cost of mass activity due to the coverage of modifiers on Pt surface.Herein,we constructed dual junctions'Pt/nitrogen-doped carbon(Pt/NC)andδ-MoC/NC to modify electronic structure of Pt via interfacial electron transfer to acquire Pt-MoC@NC catalyst with electron-deficient Pt nanoparticles,simultaneously endowing it with high mass activity and durability of alkaline HOR.Moreover,the unique structure of Pt-MoC@NC endows Pt with a high COtolerance at 1,000 ppm CO/H_(2),a quality that commercial Pt-C catalyst lacks.The theoretical calculations not only confirm the diffusion of electrons from Pt/NC to Mo C/NC could occur,but also demonstrate the negative shift of Pt d-band center for the optimized binding energies of*H,*OH and CO.
基金supported by the National Key Research and Development Program of China(2021YFB4001200)the National Natural Science Foundation of China(22272121,21972107)the Natural Science Foundation of Hubei Province(2020CFA095)。
文摘The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.
基金National Natural Science Foundation of China,Grant/Award Numbers:62105083,22109034,22109035,52164028Start-up Research Foundation of Hainan University,Grant/Award Numbers:KYQD(ZR)-20008,KYQD(ZR)-20082,KYQD(ZR)-20083,KYQD(ZR)-20084,KYQD(ZR)-21065,KYQD(ZR)-21124,KYQD(ZR)-21125+4 种基金Basic and Applied Basic Research Foundation of Guangdong Province,Grant/Award Number:2019A1515110558Hainan Provincial Postdoctoral Science Foundation,Grant/Award Number:RZ2100007123Hainan Province Science and Technology Special Fund,Grant/Award Numbers:ZDYF2020037,ZDYF2020207Hainan Provincial Natural Science Foundation,Grant/Award Numbers:222MS009,222RC548The specific research fund of The Innovation Platform for Academicians of Hainan Province。
文摘As a carbon-free energy carrier,hydrogen has become the pivot for future clean energy,while efficient hydrogen production and combustion still require precious metal-based catalysts.Single-atom catalysts(SACs)with high atomic utilization open up a desirable perspective for the scale applications of precious metals,but the general and facile preparation of various precious metal-based SACs remains challenging.Herein,a general movable printing method has been developed to synthesize various precious metal-based SACs,such as Pd,Pt,Rh,Ir,and Ru,and the features of highly dispersed single atoms with nitrogen coordination have been identified by comprehensive characterizations.More importantly,the synthesized Pt-and Ru-based SACs exhibit much higher activities than their corresponding nanoparticle counterparts for hydrogen oxidation reaction and hydrogen evolution reaction(HER).In addition,the Pd-based SAC delivers an excellent activity for photocatalytic hydrogen evolution.Especially for the superior mass activity of Ru-based SACs toward HER,density functional theory calculations confirmed that the adsorption of the hydrogen atom has a significant effect on the spin state and electronic structure of the catalysts.
基金supported bythe National Key Research and Development program of China(2021YFB4001200,2018YFB1502302)the National Natural Science Foundation of China(21972107)+1 种基金the Fundamental Reseearch Funds for the Central Universities(2042022kf1179)the Natural Science Foundation of Hubei Province(2020CFA095)。
文摘Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte fuel cells(APEFCs).Herein,we report the synthesis of amorphous RuCr nanosheets with different molar ratios and their HOR performances under alkaline media.We find a volcano correlation between the Cr content in RuCr nanosheets and their alkaline HOR performance.Experimental results and density functional theory(DFT)calculation reveals that the optimized Cr content in RuCr nanosheets could lead to the optimum hydroxide binding energy(OHBE),contributes to their remarkable alkaline HOR performance with mass activity of 568.1 A·gPGM^(–1) at 50 mV,13-fold higher than that of Ru catalyst.When RuCr nanosheet is further used as the anodic electrocatalyst,a peak power density of 1.04 W·cm^(–2 )can be achieved in an APEFC.
基金supported by the National Key R&D Program of China(2020YFA0406104,2020YFA0406101)the National MCF Energy R&D Program of China(2018YFE0306105)+5 种基金the Innovative Research Group Project of the National Natural Science Foundation of China(51821002)the National Natural Science Foundation of China(51725204,21771132,51972216,52041202)the Natural Science Foundation of Jiangsu Province(BK20190041)the Key-Area Research and Development Program of Guang Dong Province(2019B010933001)the Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 Project。
文摘The regulation of interface electron-transfer and catalytic kinetics is very important to design the efficient electrocatalyst for alkaline hydrogen oxidation reaction(HOR).Here,we show the Pt-Ni alloy nanoparticles(PtNi_(2))have an enhanced HOR activity compared with single component Pt catalyst.While,the interface electron-transfer kinetics of PtNi_(2)catalyst exhibits a very wide electron-transfer speed distribution.When combined with carbon dots(CDs),the interface charge transfer of PtNi_(2)-CDs composite is optimized,and then the PtNi_(2)-5 mg CDs exhibits about 2.67 times and 4.04 times higher mass and specific activity in 0.1 M KOH than that of 20%commercial Pt/C.In this system,CDs also contribute to trapping H^(+)and H_(2)O generated during HOR,tuning hydrogen binding energy(HBE),and regulating interface electron transfer.This work provides a deep understanding of the interface catalytic kinetics of Pt-based alloys towards highly efficient HOR catalysts design.
基金financially supported by the National Key Research and Development Program of China(2018YFB1502503)the Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)+3 种基金the Shenzhen Key Laboratory Project(ZDSYS201603311013489)the Shenzhen Science and Technology Projects for Sustainable Development(KCXFZ202002011010317)the Foundation Research Project of Shenzhen(JCYJ20200109141216566)supported by the Center for Computational Science and Engineering at Southern University of Science and Technology。
文摘The hydrogen evolution reaction(HER)is the cathodic process of water splitting,and its reverse,the hydrogen oxidation reaction(HOR),is the anodic process of an H-Ofuel cell;both play important roles in the development of hydrogen energy.The rational design and scalable fabrication of low-cost and efficient bifunctional catalysts for the HER/HOR are highly desirable.Herein,ultrasmall Mo-Ru nanoalloy(Mo_(0.5)Ru_(3)and Mo_(0.5)Ru_(3))particles uniformly distributed on mesoporous carbon(MPC)were successfully synthesized by a simple method that is easy to scale up for mass production.After the incorporation of Mo atoms,the as-prepared Mo_(0.5)Ru_(3)and Mo_(0.5)Ru_(3)nanoalloys maintain a hexagonal-close-packed crystal structure.In acidic media,Mo_(0.5)Ru_(3)exhibits excellent Pt-like HER and HOR activity,as well as good stability.Density functional theory(DFT)calculations reveal that the H adsorption free energy(ΔG)on the Mo_(0.5)Ru_(3)(001)surface(-0.09 eV)is much closer to zero than that of metallic Ru(-0.22 eV),which contributes to the enhanced catalytic activity.In alkaline media,Mo_(0.5)Ru_(3)also presents outstanding HER and HOR activity,even significantly outperforming Pt/C.The DFT results confirm that optimal binding energies with H*and OH*intermediate species,and low energy barriers in the water dissociation and formation steps,efficiently accelerate the alkaline HER/HOR kinetics of Mo_(0.5)Ru_(3).This study provides a new avenue for the scalable fabrication of high-efficiency bifunctional electrocatalysts for the HER and HOR in both acidic and alkaline media.
基金financially supported by the National Natural Science Foundation(91963109)the Fundamental Research Funds for the Central Universities(2019kfyRCPY100)supported by the Analytical and Testing Center of Huazhong University of Science&Technology。
文摘Precisely controlling the crystalline phase structure and exposed facets at the atomic level opens up a new avenue for efficient catalyst design.Along this line,we report an unconventional face-centered cubic(fcc)Ru with twinned structure and stacking-fault defects as a competent electrocatalyst towards alkaline hydrogen oxidation reaction(HOR),which is now a major obstacle for the commercialization of anion exchange membrane fuel cells(AEMFC).With conventional hexagonal close packing(hcp)Ru as the counterpart,a novel scope from the phase-engineering is introduced to identify the activity origin and provide fundamental understanding of the sluggish HOR kinetics in alkaline medium.Systematic electrochemical analysis assisted by deconvoluting the hydrogen(H)desorption peaks indicates the superior performance of fcc Ru origins from the structure defects and higher proportion of the most active sites.DFT calculations,together with CO-stripping voltammograns further corroborate the stronger hydroxyl species(OH^(*))affinity lead to the higher activity on these sites.Meanwhile,it also demonstrates the H^(*)adsorption/desorption on polycrystalline Ru among the conventional"hydrogen region"is accompanied by the surface bound OH^(*)in alkaline medium,which is of great significance for subsequent alkaline HOR exploration and catalyst design.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.2017R1D1A1B03032033 and 2020R1C1C1010386)“Leaders in INdustry-university Cooperation+”project supported by the Ministry of Education and National Research Foundation of Korea。
文摘In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBCs).For this purpose,polyethyleneimine(PEI) was added onto the reduced graphene oxide and CoPc composite(RGO/CoPc) to create abundant NH2 axial ligand groups,for anchoring the Co core within the CoPc.Owing to the PEI addition,the onset potential of the hydrogen peroxide oxidation reaction was shifted by 0.13 V in the negative direction(0.02 V) and the current density was improved by 1.92 times(1.297 mA cm^(-2)),compared to those for RGO/CoPc(0.15 V and 0.676 mA cm^(-2),respectively),due to the formation of donor-acceptor dyads and the prevention of CoPc from leaching out.The biocatalyst using glucose oxidase(GOx)([RGO/CoPc]/PEI/GOx) showed a better onset potential and catalytic activity(0.15 V and 318.7 μA cm^(-2)) than comparable structures,as well as significantly improved operational durability and long-term stability.This is also attributed to PEI,which created a favorable microenvironment for the enzyme.The maximum power densities(MPDs) and open-circuit voltages(OCVs) obtained for HPFCs and EBCs using the suggested catalyst were 105.2±1.3 μW cm^(-2)(0.317±0.003 V) and 25.4±0.9 μW cm^(-2)(0.283±0.007 V),respectively.This shows that the amine axial ligand effectively improves the performance of the actual driving HPFCs and EBCs.
基金supported by the National Natural Science Foundation (No. 91963109)。
文摘Controlling the particle size of catalyst to understand the active sites is the key to design efficient electrocatalysts toward hydrogen electrode reactions including hydrogen oxidation and evolution(HOR/HER).Herein, the hydrogen and hydroxyl adsorption on Ru/C could be effectively tuned for HOR/HER by simple controlling the particle sizes. It is found that the metallic Ru(Ru0) is the active site for HOR/HER, while oxidized Ru(Rux+) will hinder the adsorption and desorption of hydrogen on the catalyst. For the HOR,catalyst with small particles is more efficient, due to it is a three-phase interface reaction of gas on the surface of the catalyst. For the HER, the metallic state of Ru is crucial. The deconvolution of hydrogen peaks indicates that the catalytic sites with low hydrogen binding energy(HBE) shoulder the majority of the HOR activity. CO stripping curve further demonstrates that the stronger hydroxyl species(OHad)affinity is beneficial to promote the HOR performance. The results indicate that the design of efficient HOR/HER catalyst should focus on the balance between particle size and metallic states.
基金supported by the National Basic Research Program of China(No.2018YFA0702001)the National Natural Science Foundation of China(Nos.22225901,21975237,and 22175162)+3 种基金the Anhui Provincial Research and Development Program(No.202004a05020073)the Fundamental Research Funds for the Central Universities(No.WK2340000101)the USTC Research Funds of the Double First-Class Initiative(No.YD2340002007)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(No.RERU2022007).
文摘Recent advancement of proton exchange membrane fuel cells has led to commercial sales of fuel-cell cars but market barrier exists because this technology heavily relies on platinum catalyst.Given the permission of adopting platinum-group-metal-free catalysts,anion-exchange membrane fuel cell has received notable attention.However,the sluggish kinetics of anodic hydrogen oxidation reaction(HOR)largely limit the cell efficiency.Although many high-performance HOR catalysts have been reported,there are analytical uncertainties in the literature concerning the assessment of the catalyst activity.Here we determine the origin of false HOR currents in the recorded polarization curves and propose a rigorous approach to eliminate them.We unveil experimentally the uncertainties of obtaining exchange current densities(j0)using Tafel plot from Bulter–Volmer equation and recommend employing the micro-polarization region method.For bulky catalysts that cannot establish a well-defined diffusion layer,we suggest applying external stirring bar to offer certain level of enforced convection and using j0 to compare the activity.
基金supported by the National Natural Science Foundation of China(Nos.U1909213,51872209,52171145,22105146)Zhejiang Provincial Special Support Program for High-level Talents(No.2019R52042).
文摘Modulating Pt surfaces through the introduction of lattice distortion emerges as immensely effective strategy that enhances the kinetics of alkaline hydrogen evolution and oxidation processes.In this study,we fabricated lattice-distorted Pt wrinkled nanoparticles(LD-Pt WNPs)for efficient hydrogen electrocatalysis.The LD-Pt WNPs not only outperform the Pt/C benchmark in hydrogen oxidation reaction,achieving an excellent mass-specific current of 968.5 mA·mg_(Pt)^(-1)(9 times that of Pt/C),but also demonstrate outstanding hydrogen evolution reaction activity with a small overpotential of 58.0 mV.Comprehensive experiments and density functional theory calculations reveal that lattice defects introduce an abundance of unsaturated coordination atoms while modifying the d-band center of Pt.This dual effect optimizes the binding strength of crucial H and OH intermediates,leading to a significant reduction in the energy barrier of the reaction bottleneck,commonly known as the Volmer step.This work unveils a fresh viewpoint on projecting and developing high efficiency electrocatalysts through defect engineering.
基金supports by the National Key R&D Program of China(No.2020YFB1505802)Ministry of Science and Technology of China(No.2017YFA0208200)+1 种基金the National Natural Science Foundation of China(Nos.22025108,U21A20327,22121001 and 22275152)start-up support from Xiamen University.We thank beamline TLS01C1(“National Synchrotron Radiation Research Center”)for providing the beam time.We acknowledge support from the Max Planck-POSTECHHsinchu Center for Complex Phase Materials.
文摘Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER)is of considerable importance for the industrial production of green and sustainable energy.Here,an ultrathin Ir-Sb nanowires(Ir-Sb NWs)protected by antimony oxides(SbO_(x))was synthesized as an efficient bifunctional catalyst for both HOR and HER under alkaline media.Except from the much higher mass activities of Ir-Sb nanowires than those of Ir nanowires(Ir NWs)and commercial Pt/C,the SbO_(x) protective layer also contributes to the maintenance of morphology and anti-CO poisoning ability,leading to the long-term cycling performance in the presence of CO.Specifically,the Ir-Sb NW/SbO_(x) exhibits the highest catalytic activities,which are about 3.5 and 4.8 times to those of Ir NW/C and commercial Pt/C toward HOR,respectively.This work provides that the ultrathin morphology and H_(2)O-occupied Sb sites can exert the intrinsic high activity of Ir and effectively optimize the absorption of OH*both in alkaline HER/HOR electrolysis.
基金supported by Center for Computational Science and Engineering at Southern University of Science and Technologyfinancially supported by the National Key Research and Development Program of China (2018YFB1502503)+3 种基金Guangdong Provincial Key Laboratory of Energy Materials for Electric Power (2018B030322001)Shenzhen Key Laboratory Project (ZDSYS201603311013489)Shenzhen Science and Technology Projects for Sustainable Development (KCXFZ202002011010317)the Foundation Research Project of Shenzhen (JCYJ20200109141216566)。
文摘Efficient,robust and cost-effective electrocatalysts that catalyze hydrogen evolution/oxidation reaction(HER/HOR)in alkaline media are highly demanded.Recently,single-atom catalysts(SACs)have emerged as new promising candidates;however,the rational design of supports and the optimization of coordination environment between supports and metal atoms are challenging.In this work,we successfully fabricate atomically dispersed ruthenium(Ru)species,which are strongly coordinated by N and S dual heteroatoms on holey graphene(RuSA/NSG),as an excellent bifunctional catalyst for HER/HOR.In alkaline media,the developed catalyst exhibits high catalytic performance with a low overpotential of 57.3 mV to drive a current density of 10 mA cm^(-1) for HER,and its mass activity is about 5.8 times higher than that of commercial Pt/C and Ru/C catalysts at an overpotential of 100 mV.Similarly,considerable HOR performance of Ru SA/NSG is verified to be superior to Pt/C and Ru/C.Furthermore,X-ray-based spectroscopy measurements and density-functional theory calculations have confirmed that,compared with Ru–N_(4),the tailored Ru–N_(4)–S_(2) with nearby S dopants can act as more active centers to greatly accelerate the sluggish HER/HOR kinetics in alkaline media.The present work provides a new atomic-level engineering strategy to modulate catalytic activities of SACs via the coordination design using dual heteroatoms on the carbon support.
基金supports by the National Key R&D Program of China(No.2020YFB1505802)the Ministry of Science and Technology of China(Nos.2017YFA0208200,and 2016YFA0204100)+2 种基金the National Natural Science Foundation of China(Nos.22025108,22121001 and 51802206)Guangdong Provincial Natural Science Fund for Distinguished Young Scholars(No.2021B1515020081)Start-up Supports from Xiamen University and Guangzhou Key Laboratory of Low Dimensional Materials and Energy Storage Devices(No.20195010002).
文摘Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction(HOR),yet its specific role is largely undecoded.Here,ultrathin Pt nanowires(NWs)are selected as models for revealing the significance of Ni modification on HOR by precisely positioning Ni on distinct positions of Pt NWs.Ni solely influences the electronic properties of Pt and thus weakens*H adsorption when it is located in the core of PtNi alloyed NWs,leading to a moderate improvement of alkaline HOR activity.When Ni is distributed in both core and surface of PtNi alloyed NWs,Ni strongly weakens*H adsorption but strengthens*OH adsorption.On the other hand,the electronic properties of Pt are hardly influenced when Ni is deposited on the surface of Pt NWs,on which the strong*H and*OH adsorptions lead to the improved HOR activity.This work reveals the significance of Ni modification on HOR,but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond.
基金financially supported by the National Natural Science Foundation of China (No.21972107)National Natural Science Foundation of Hubei Province (No.2020CFA095)+1 种基金the National Natural Science Foundation of Jiangsu Province (No.BK20191186)Yangzhou Key Research Development Program (No.YZ2019025)。
文摘Exploring highly efficient electrocatalysts and understanding the reaction mechanisms for hydrogen electrocatalysis,including hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) in alkaline media are conducive to the conversion of hydrogen energy.Herein,we reported a new strategy to boost the HER/HOR performances of ruthenium (Ru) nanoparticles through nitrogen (N) modification.The obtained N-Ru/C exhibit remarkable catalytic performance,with normalized HOR exchange current density and mass activity of 0.56 m A/cm^(2)and 0.54 m A/μg,respectively,about 4 and 4.5 times higher than those of Ru/C,and even twofold enhancement compared to commercial Pt/C.Moreover,at the overpotential of 50 m V,the normalized HER current density of N-Ru/C is 5.5 times higher than that of Ru/C.Experimental and density functional theory (DFT) results verify the electronic regulation of Ru after N incorporation,resulting in the optimized hydrogen adsorption Gibbs free energy (ΔG_(H*)) and hence enhancing the HOR/HER performance.